Known in the present state of the art are surgical suturing instruments (otherwise called stapling machines) for placing linear sutures, comprising a body having a hook which carries a die with a number of recesses, a staple head with a staple magazine and a staple ejector, a tissue restrictor and actuators of the staple head and the ejector [(cf., e.g., U.S. Pat. No. 3,494,533 Int. Cl. B 31b 1/00 issued in 1970 to David T. Green et al.)[.
The free end of the hook to which the die is held, is arranged in a cantilevered manner; hence the construction of the stitching portion of the instrument is inadequately rigid in three mutually square directions, i.e., in the direction of suturing and in a plane square thereto. Since the stiching mechanism of the instrument sustains head loads during the sturing process, resulting from compression of the walls of organs being sutured and once-through deformation (bending) of a great numer of staples, a quality suture cannot be obtained unless a stable mutual arrangement of the die recesses and the magazine staple slots is provided. The required rigidity of the construction to meet this important prerequisite is attained in said instruments due to considerably enlarged cross-sectional dimensions of the elements of the hook, the body frame, and some other components of the stitching mechanism. Comparatively large dimensions of the stitching portion affect adversely the maneuvrability of the instrument and render it inapplicable in narrow body cavities.
Moreover, a relatively large width of the die and staple magazine requires respectively more space for the instrument to set in the suturing position and leads to a comparatively great distance from the staple suture to the line of cut on the tissues carried out along the magazine and die edge and hence to a rude suture obtained. And conversely, when the cross-sectional size of the hook and other components on the stitching mechanism is reduced, this might result in considerable deformation of the mechanism components during the suturing process, an inadmissible increase in the suturing gap, or distortion of the true shape of stitches applied.
The aforementioned disadvantages are eliminated in surgical instruments for placing linear sutures, incorporating a body having a closed frame.
One more prior-art surgical instrument for placing linear sutures is known to comprise a body with a closed rectangular frame, a die provided with a plurality of recesses and secured on one side of the frame, and a staple head set in the frame opposite to the die and mounted movably with respect thereto. A detachable staple magazine is fixed stationary in the staple head, as well as a staple ejector is set therein, which is so arranged as to correspond to the magazine staple slots. The staple head has an actuator accommodated in the instrument body, and the staple ejectro actuator is located in the staple head body [(cf., e.g., U.S. Pat. No. 4,378,901 Int. Cl. B 25C 5/00 issued in 1983 to Ernest M. Akopov and July G. Shaposhnikov)].
High-rigidity construction of the body with a closed rectangular frame makes it possible, with the load upon the stitching mechanism remaining unaffected in the course of multistaple suture application, to considerably reduce deformation of the instrument components and provide for a stable mutual arrangement of the magazine staple slots and the die recesses, a feature that draws distinction between the instrument unde discussion and its analogues. The instrument is able to ensure higher-quality formation of suture stitches and attain better tightness of the suture and hence its better hermeticity and hemostatic character. Higher rigidity of the construction makes it possible to reduce the cross-sectional dimensions of the instrument stitching mechanism and thereby to render it more maneuvrable in the operative wound, to decrease the distance from the suture to the line of out of the tissue involved and to obtain a more delicate suture.
However, the extreme staple slots of the magazine and the respective extreme die recesses are spaced somewhat apart from the frame lateral side. Besides, since the instruments of the character considered herein are designed for placing double-row sutures with one of the rows offset relative to the other (the so-called staggered-stitch sutures), the distance between the extreme paired magazine slots and die recesses of one row and the respective slots and recesses of other row is as a rule adopted to be half the pitch of stitches in each row. Hence the suture placed on a considerable extension from the frame lateral side is in fact a single-row one.
The aforementioned construction particulars of the instrument under discussion result in that when the instrument is used for suturing an organ whose semiperimeter at the place of suture application equals the distance between the frame lateral sides, the marginal portions of the organ fail to be stitched with staples, or are stitched with a single-row suture over some length. Hence neither hermetic tightness nor hemostasis of the suture placed on the extreme portions of the stitched-up organ is attained after the magazine and die have been brought apart and the instrument has been withdrawn from the operative wound.
In practical surgery the semiperimeter of a compressed organ may frequently be in excess of the distance between the lateral sides of the frame of an instrument applied, since it is hard to estimate by eye the size and semiperimeter of a hollow organ when compressed, and to compare its size with the distance between the lateral frame sides, especially when manipulating deeply in the wound and observability of the operative field is hampered. In such a situation the aforesaid disadvantage is still more demonstrable, inasmuch as the marginal tissues of the organ operated upon are compressed lengthwise the line of the suture being placed and are free to spread out as soon as the instrument is withdrawn from the operative wound, whereby the length of the non-sutured section is still increased.
Whenever good observation of the operative field is provided and an adequately convenient access to the suture is obtained, imperfections of a mechanical suture are quite evident, and the surgeon is in a position of placing auxiliary manual sutures on the extreme sections of the operative wound to provide hermetic tightness and good hemostasis of the suture. However, the instrument proves to be inapplicable in case of surgery under hard-of-access conditions deeply in a narrow operative field where visual control of the suture is difficult, or when it is practically impossible to place additional sutures on the extreme wound sections due to difficulties in passing a thread-fitted needle and performing manual-suture application manipulations. The instrument is also inapplicable in cases where a short stump of the stitched-up organ slips off after a mechanical suture has been applied and gets obscured by the surrounding tissues and organs, or when any further effects with a needle an thread upon delicate easily vulnerable tissues, e.g., those of infants. Nonsutured extreme sections of the stitched-up organs might develop profuse postoperative bleeding, disturbed aseptics, or some other complications that might happen fatal to a patient.